Process for the manufacture of iron and steel



H. LANG.

PROCESS FOR THE MANUFACTURE OFJRON AND STEEL.

APPLICATION FILED JULY 7, 1919.

1,340,548, Patented May 18,1920.

" Hcrbcrilarzgi IN VEN TOR A TTORNE Y .HERBERT LANG, OF OAKLAND, CALIFORNIA.

rnoonss r03 THE MANUFACTURE or IRON-AND STEEL.

Application filed July 7, 1919. Serial No. 309,225.

To all whom it man Concern Belt known t at I, HERBERT LANG, a

I citizen of theUnited States, residing at the city of Oakland, in the county of Alameda and State of California, have invented certain new and useful Improvements in Processes for the Manufacture of Iron and Steel, of which the following is a specification.

My invention relates more particularly to the manufacture of metal from the ores of ironby the use of such fuels as petroleum, asphaltum, tar, pitch and the solid and liquid out'residues of gas works and oil refineries. Coal or coke screenings may also be used if they are reduced to a pulverulent condition. In my process I obtain the metal in the form suitable for immediate rolling or casting, by combiningthe operations of reducing and fusing,and also by this process I can manufacture steel or iron vof-any desired composition directly from'theore.

I am'aware that ironhas for'a long time been made by reducing itsores by means of the fuels above named, the product being the so-called sponge iron, the latter, however,

has a great propensity to"oxidiz'e, making it unsuitable for rolling or any .operation'inv which it must be "heated and worked upon in contact with the atmosphere.

lVith the above objects in view the invention consists. in the novel processes and' features herein described and more specifically pointed out in the appended claims.

Referencebeing had to the accompanying drawing;

Figure 1 is a. diagrammatic view of the apparatus used in carrying out my process.

Fig. 2 is a view vin'cross section-of the container .in which the reduction of the ore takes place. 1

In carryingout my process, I takeiron ore (oxid of iron) and pulverize it rather finely. If the ore is hard and dense, such as magnetite, I reduce it to a size, as for example, that will pass through a screen having 16. meshes to a lineal inch. When a so ter and more porous grade of ore is used, Ido not pulverize the ore so finely, as I have found that ores of this description are more easily reduced. I then mix the pulverized ores with one or more of the carbonaceous materials above mentioned, adding always a certain amount of liquid carbonaceous ingredient so as to cement the mass together.

I thoroughly intermix with the oil and fuel a'quantity of basic material such as burnt limestone or burnt dolomite, the prin- Specification of Letters Patent. Patented llay 18, 1920.

cipal function of which is to remove the phosphoric acid and sulfur and act as a In making up the mixture I add a little more carbon than-necessary to reduce the ore, the excess being for the purpose of 'carburizing the reduced metals making it fusible at a lower temperature.

The reduction of the ore is carried on within closed receptacles G. For this purpose 1 I' prepare cast iron or steel vessels which themselves are preferablyi made from metal formed by this process. he containers are closed at one end and into the cavity of the containers is packed the charge of mixed ore, fuel, and basic material as above described. These. containers may be made tubular in form, but I- do not wish it to be understood that'I limit myself to this form, or to the ca'sting of the containers from metal made by this process. The charge. of

mixed ore, fuel andfiux is. carefully tamped- Y so to. exclude as muchair. as possible, and

the other end of the container closed by a plug. H for the purpose of "excluding oxidizing gases. The material ordinarily used for this purpose is a mixture of tar and ground;

burnt dolomite or" limestone. 1 When this container'is heated, the carbonaceous material burnsout leaving the plug sufficiently porous that the gaseous products generated within the containers may escape therefrom. The reducing furnace is denoted by A, and this furnace has special reference to the ".form of containers used. It may be built on a slight incline in order that the containers may roll towardthe lower end thereof, or mechanical means may beprovided'to move the container from one end to the other. As here shown the lower end of this furnace is connected to a fusing chamber B,

constructed on the lines of an open hearth furnace. Between the reducing'furnace and the fusing furnace is a damper C of fireresisting material, which may be manipu lated, so. that heated gases may pass from. the furnace B to the furnace A, in such quantities as to impart the degree of heat to the contents of the latter that has been found most efiicient. V

In the carrying out of my process the upper end of the furnace A which ishereinaf ter spoken of as the reducing furnace, is connected by fiues D with regenerators E. These regenerators are of the ordinary checker brick work construction, and have their opposite ends connected to a stack F or other draft inducing means.

The flues D are connected as shown at J and K with the furnaces A and B respectively and the various flues 'are provided with regulating dampers L. Other flues M extend from the regene ator to the burner N and these flues are also provided with regulating dampers. i

11 use the charged cylindrical receptacles are introduced into the upper end of the reducing chamber where they meet the heated gases from the furnace B. By admitting the heating gases at the lower end of the furnace, this end is kept at a higher temperature than the other end, which gives the greatest efficiency, since the reducing temperature should be a low one, and the proper heating of the containers and their contents requires a considerable time. As the containers move from the rear end of the furnace toward the damper C, they are gradually raised in temperature and reaction takes place between the oxid of iron, the carbon, and the basic material which results in the ore being reduced and the driving off of carbon dioxid, carbon monoxid, hydrogen,

nitrogen and some hydrocarbons.

These gases commingle with the heating gas and pass through the flue D to the regencrating chambers. The hot gases from the furnace B which are not passed through the chamber A, are led out through the flue K to one or the other of the regenerators. Fuel gas is received through the fiue O, and the heated air to support combustion through the flue D.

It will now be understood that the object of reducing the iron ore within the closed containers is to permit the reduction to take place out of contact with oxidizing gases. Furthermore, the use of the containers provides a convenient means of moving the charge through the reducing furnace, obviates the necessity of removing the spongy mass of reduced iron from the reducing furnace into contact with the atmosphere and conserves heat.

In order to avoid the necessity of adding ferro-manganese or spiegeleisen to the fluid .steel, I prepare a number of containers with special charges containing manganese ore and suitable reducing and fluxing agents. These containers are fed into the reducing chamber at suitable intervals so that when fed into the fusion furnace the resultant mass will have the desired composition.

Having thus described my invention I.

claim as new, and wish to cover by Letters Patent:

1. The process of making iron and steel which consists of heating iron ore and a reducing agent in a closed iron container,

transferring said container and the reduced iron ore and a reducing agent in closed iron containers, gradually heating said containers and their charges to a reducing temperature, and then transferring them to a melting furnace without bringing them into contact with an oxidizing agent.

f. The process of making'iron or steel which consists of heating an intimate mixture of iron ore, basic material and an excess ofreducing material in closed iron containers, gradually bringing said containers and their contents to a'reducing temperature by passing-them through the exhaust gas from a fusion furnace, and then depositing said containers into the fusion furnace to melt them and their contents.

5. The process of manufacturing iron and steel consisting of heating iron ore and an excess of carbonaceous material in a fusible iron container and transferring said container to a melting furnace without contact with the atmosphere, and there liquefying said container and its contents.

6. The process of manufacturing iron and steel which consists of tightly packing iron containers with an intimately mixed mass of iron ore and a reducing agent, closing said containers with a porous plug containing a reducing agent, gradually bringing said containers and their contents to a reducing temperature, transferring said containers to a melting furnace, and then liquefying said containers and the reduced mass therein.

7. The process of manufacturing alloy steel, which consists of heating iron ore and a reducing agent in closed iron containers to a reducing temperature, heating ores of the alloy metals in closed containers with a reducing agent, transferring containers of the two kinds'to a melting furnace in such proportions as to give the desired composition of steel, and then liquefying said containers and their contents.

In testimony whereof I aflix my signature.

HERBERT LANG. 

